Re: U.S. threatened to bomb Pakistan after 9/11: Musharraf
Question is not about fighting USA, but question is, for what?
If USA attacks Pakistan, Pakistan will defend by all means, but that does not mean inviting such attack for something unworthy and immaterial like Taliban.
As for Taliban, best Musharraf did was left them on Allah. It seems Allah sent USA as Qahar-e-ilahi on Taliban that made tora-bora of them Taliban. That qahar-e-ilahi could have fallen on Pakistan too but Allah gave hadayah to Musharraf that saved Pakistan from that Qahar-e-ilahi that fell on Taliban and later on Iraq.
Just imaging, if such war happens, American forces would not even put their foot on Pakistan soil but would just going to blockade Pakistan trade as they would control sea around us (no oils, no medicines, no military equipments or any essentials Pakistan needs from import), put sanctions on all goods to Pakistan and would rely on heavy bombing. Pakistan attack would be different from Afghanistan or Iraq, as American need to change regime would not going to be a desire but USA purpose would be just to destroy Pakistan as a nation.
Such war would be only one sided. American missiles would be hitting Pakistan from Saudi Arabia and sea around Pakistan (from American ships) and bombs from bombers flying sky-high over Pakistan, while Pakistanis would be dying in masses. Meanwhile some pathetic Pakistanis and other so-called sympathisers sitting safely in their western countries (some even in USA) would be watching Pakistani miseries on TV doing drawing room talking that how evil USA is (as they do referring to Iraqi miseries and USA action there).
Obviously, Pakistan has no means to defend themselves from such attacks (Pakistan makes little defence materials for such attacks. There is no comparison as technologically very advanced USA spends over 500 billion dollars directly (1000 billion dollars directly and indirectly) on defence every year whereas underdeveloped Pakistan spends less than 4 billion dollars a year on defence.
If west just stops all military supply to Pakistan and liberally start supplying military supply to India (India spends around 25 billion dollars a year on defence), the imbalance would be such that it would become impossible to defend Pakistan even from India.
[Note: Most of Pakistani military equipments are American made (even western European made equipments are prone to American influences) and even sanctions on spare parts can heavily deteriorate Pakistan military capability].